The procedure of estimating the object rotation \(R_{wo}\)  is shown in the lower part of Figure REF . We first adopt a template-matching (TM)-based approach, LINE-2D [1]}, for obtaining the per-frame rotation measurement \(R_{co, k}\) . The acquired measurements from multiple viewpoints are then integrated into an optimization scheme. We handle the rotational symmetries explicitly given the object CAD model. To counteract the measurement uncertainties (e.g., from appearance ambiguities), a max-mixture formulation [2]} is used to recover a globally consistent set of object pose estimates. Note that the acquisition of the rotation measurement \(R_{co, k}\)  is not limited to the LINE-2D [1]} or TM-based approaches and can be superseded by other holistic-based methods [4]}, [5]}.
<FIGURE>